Impeovement in ships  compasses



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JAMES, EARL 0F GAITHNESS, Y0E MIDDLESEX COUNTY, ENGLAND.

Letters Patent No.`70,520, dated November 5, 1867. I I

IMPROVEMENT IN SHIPS GOMPASSES.

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TO ALL WHOM IT MAY CONOERN: v

Be it lknown that I, JAMES, EARL 0F CAITHNESS, of Middlesex county, England, have invented an Improvement in. Ships Compasses; and I do hereby declare the following to'be a full, clear, and exact description of theV same. I

This invention relatesto amode of suspending ships compasses with a view to prevent undue oscillation in heavy seas, and consists essentially in attaching to the compass-box, or case containing the card or needle, a weighted rod or pendulum, which is allowed to swing freely iu a ball-and-socket joint situated as close as possible to the compass. The socket for the ball-joint is contained in the upper part of a bnnacle, or other -convenient frame or support, which will allow the free play or swing of the pendulum. The bob or weight of the pendulum is made adjustable along the rod by, a setscrew, or other convenient contrivance, so as to admit of alteration or adjustment. By this contrivance the compass is constantly maintained in a horizontal position, as whatever may be the motion of the ship the pendulum will always remain perpendicular.

In order to enable others skilled in the art to makeand apply mylinvention, I will now describe 'its oonstruction and operation, reference beinghad to the accompanying drawing, which forms a part of this specification, and in which- Figure 1 is a vertical section f a compass with my improvement, and

Figure 2 a. plan view. v

A is the deck, bridge, or other part of a ship, to which is secured the binnacle or framev B, the latter being so constructed that the weighted 4pendulum C may swing freely in the roughest weather. Near the upper endof the rod of the pendulum there is a ball, D, which turns freely in any direction' in a socket, E, carried by and secured to the top of the binnacle or support in any convenient or suitable manner. This socket may `he made in two halves, screwed together, so that one' half may belremoved for the facility of introducing the ball into its seat. .Above this ball-and-socket joint, and to the extremity of the pendulum-rod C, I secure in `any convenient manner the compass-box F,of any desired form, containing the ordinary pivoted card or needle G, protected by a glass in the usual manner. The pendulum may be made of any length, but I have found a length of about two feet six inches from the centre of oscillation to the centre of the weight orpendulum-bob H to answer well in practice, and I prefer to make such weight adjustable along the pendulum-rod, and to secure it at any desired height by means of a set-screw, I, or equivalent device.

Iv claim as my invention, and desire to secure by Letters Patent- The combination of a mariners compass and a weighted pendulum secured to the compass-box, and havingl near the upper end a ball which fits ina stationary socket, all substantially as and'for the purpose described.

Iny testimony Vwhereof I have signed my name to this specification in the presence of two subscribing witnesses.

CAITHNESS.

Witnesses:

W. GORTON, Clerk to 2LT. Johnson, 47 Lncolns Inn Fields, London. J. J. VIDLER, y 

